方法：选取2014-02/2019-03在天津市眼科医院行超声乳化联合IOL植入术的白内障患者31例31眼，所有患者既往均接受过近视角膜屈光手术(LASIK/PRK)，白内障术后至少随访6mo进行验光。比较不同角膜半径范围(2.0、3.0、4.0、4.5、5.0mm)的等效角膜曲率(EKR)联合Haigis公式计算近视术后IOL屈光度的准确性，得到改良Haigis公式，进而比较改良Haigis公式与Barrett true K、Haigis-L、Shammas-PL公式计算近视术后IOL屈光度的准确性。

结果：4.0mm EKR联合Haigis公式计得到的术后中位数绝对屈光误差(MedAE)和平均绝对屈光误差(MAE)明显低于4.5mm EKR和5.0mm EKR(均P<0.01)，且术后屈光误差(PE)在±0.50、±1.00、±2.00D范围内的患者百分比也明显高于4.5mm EKR和5.0mm EKR(均P<0.05)，故将4.0mm EKR联合Haigis公式命名为改良Haigis公式。改良Haigis、Barrett true K、Haigis-L、Shammas-PL公式的术后MedAE分别为0.58(0.27，1.12)、0.51(0.30，1.15)、1.26(0.67，1.72)、0.77(0.36，1.45)D，术后PE在±0.50D和±1.00D内的患者百分比分别为42%和74%、52%和71%、22%和42%、32%和61%。在眼轴长度(AL)<27mm和27mm≤AL≤30mm患者中，Haigis-L公式的术后PE值高于改良Haigis公式(P=0.019、0.0142)和Barrett true K公式(P=0.002、<0.001)。在27mm≤AL≤30mm患者中，Haigis-L公式的术后PE值高于Shammas-PL公式(P=0.003)，其余各组间均无明显差异(P>0.05)。

结论：4.0mm EKR联合Haigis公式可以用于近视LASIK/PRK术后IOL屈光度的计算，其准确性与Barrett true K公式相当，且AL越长，患者术后发生远视漂移的可能性越高。

METHODS: The clinical records of 31 patients(31 eyes)who firstly accepted myopic corneal refractive surgery(LASIK/PRK)and then underwent phacomulsification was combined with IOL implantation in Tianjin Eye Hospital between February 2014 and March 2019 were finally enrolled in this study. Postoperative refraction was performed at least 6mo after cataract surgery. To compare the accuracy of equivalent keratometry readings(EKR)of different corneal radius(2.0, 3.0, 4.0, 4.5, 5.0mm)combined with the Haigis formula to calculate the IOL diopter after myopia, obtain the modified Haigis formula, and then compare the modified Haigis formula with the accuracy of Barrett true K, Haigis-L and Shammas-PL formulas for calculating IOL diopter after myopia.

RESULTS: The median absolute error(MedAE)and mean absolute error(MAE)of 4.0mm EKR Haigis formula was significantly lower than that of 4.5mm and 5.0mm EKR(all P<0.01). And the refractive prediction error(PE)also had a higher percentage of eyes in ±0.50D, ±1.00D and ±2.00D than that of 4.5mm EKR and 5.0mm EKR(all P<0.05). Thus, 4.0mm EKR Haigis formula was considered as the modified Haigis formula. The Postoperative MedAE of modified Haigis, Barrett true K, Haigis-L and Shammas-PL were 0.58(0.27, 1.12), 0.51(0.30, 1.15), 1.26(0.67, 1.72), 0.77(0.36, 1.45)D respectively. Moreover, the percentages of eyes with postoperative PE in ±0.50D and ±1.00D of the above formulae were 42% and 74%, 52% and 71%, 22% and 42%, 32% and 61% respectively. In eyes with axial length(AL)<27mm and 27mm≤AL≤30mm, the postoperative PE value of Haigis-L formula was higher than that of modified Haigis(P=0.019, 0.0142)and Barrett true K formula(P=0.002, <0.001 ). In patients with 27mm≤AL≤30mm, the postoperative PE value of Haigis-L formula was higher than that of Shammas-PL formula(P=0.003), and there was no significant difference among the other groups(P>0.05).

CONCLUSION: Haigis formula combined with the 4.0mm EKR can be used to calculate the IOL power in eyes after myopic LASIK/PRK, and its accuracy is comparable to the Barrett true K formula. However, the longer the AL is, the higher the possibility of hyperopic drift postoperatively might occur with the modified Haigis.